Writing instrument



FIG. 1 is a front elevational view of a writing instrument showing the new design;

FIG. 2 is a side elevational view of the writing instrument as shown in FIG. 1;

FIG. 3 is a top plan view of the writing instrument as shown in FIG. 1; and,

FIG. 4 is a bottom plan view of the writing instrument as shown in FIG. 1. 

We claim the ornamental design for a writing instrument, as shown. 